In the United States, detection of squamous carcinoma in situ (CIS) by screening has led to reduced rates for invasive squamous carcinoma and lower mortality. Adenocarcinoma in situ (AIS) rates also have increased, but invasive cervical adenocarcinoma rates have not declined similarly. To make inferences about the effectiveness of screening, the authors assessed mortality trends for squamous and adenocarcinoma in relation to incidence of these tumors, incidence of their precursors and survival.
Using data from the Surveillance, Epidemiology, and End Results program (SEER), the authors tabulated incidence per 105 woman-years for invasive carcinomas (1976–2000) and for CIS and AIS (1976–1995) by age (< 50 years, ≥ 50 years) and race (whites, blacks). Cumulative relative survival rates were tabulated for 1976–1995 and mortality rates were estimated for 1986–2000.
Among all groups, CIS rates approximately doubled whereas rates for invasive squamous carcinoma declined. Among younger whites, mortality declined from 1.12 to 0.93, and for older whites, mortality decreased from 5.02 to 3.82. Among younger blacks, mortality for squamous carcinoma decreased from 2.69 to 1.96. Among older blacks, the mortality rates declined from 14.88 to 9.15. Although AIS rates have increased dramatically among whites (all ages) and younger blacks, adenocarcinoma incidence and mortality rates have not changed greatly. Survival for patients did not change greatly within these age-race groups.
The authors concluded that increases in CIS seemed disproportionately large compared with improvements in mortality rates for squamous carcinoma. Despite increased reporting of AIS, declines in mortality for cervical adenocarcinoma have not been demonstrated conclusively. However, future analyses are required to evaluate these trends more completely. Cancer 2005. Published 2005 by the American Cancer Society.